Amino Acid Metabolism and Nitrogen Balance

These flashcards cover key terms and concepts related to amino acid metabolism, nitrogen balance, urea cycle, and associated biochemical processes critical for human health.

Amino Acid Catabolism

The breakdown of amino acids for energy, primarily occurring in the liver.

Transamination

A reaction that transfers an amino group from one amino acid to an α-keto acid, producing another amino acid and a new α-keto acid.

Urea Cycle

A metabolic pathway in the liver that converts ammonia into urea for safe excretion.

Glutamate

An amino acid that acts as a carrier of amino groups and is involved in nitrogen metabolism.

Essential Amino Acids

Amino acids that cannot be synthesized by the body and must be obtained from the diet.

Non-essential Amino Acids

Amino acids that can be synthesized by the body and do not need to be obtained from food.

Ammonia Toxicity

A condition caused by elevated ammonia levels in the blood, leading to serious neurological impairment.

Ammonia (NH₃)

A toxic by-product of amino acid catabolism that must be converted into urea by the liver.

CPS-1 (Carbamoyl Phosphate Synthetase I)

The key regulatory enzyme in the urea cycle that initiates the conversion of ammonia to urea.

Glutamine

An amino acid that serves as a major carrier of nitrogen and is formed from glutamate and ammonia.

Vitamin B6 (Pyridoxine)

A cofactor essential for transamination reactions and amino acid metabolism.

Maple Syrup Urine Disease (MSUD)

A disorder caused by a deficiency in the enzyme complex BCKDH, leading to toxic accumulation of branched-chain amino acids.

PKU (Phenylketonuria)

A genetic disorder resulting from a deficiency in the enzyme phenylalanine hydroxylase, causing neurotoxicity.

Nitrogen Balance

The difference between nitrogen intake and nitrogen excretion, crucial for proper protein metabolism.

Gut Microbiome

The community of microorganisms in the gastrointestinal tract that influence amino acid metabolism and overall health.